Steam trap



. mentor \bm STEAM TRAP w. B. CLIFFORD Filed Jan. 26, 1940 March 17, 1942.

Patented Mar. 17, 1942 STEAM TRAP Walter B. Clifford, Boston, Mass, assignor to Clifford Manufacturing (30., Boston, Mass., a

corporation of Delaware Application January 26, 1940, Serial No. 315,864

3 Claims.

The present invention relates to steamv traps, and more particularly to devices of this character employing the thermostatic principle of operation.

The purpose and object of the invention is to reorganize and improve traps of the general character, to insure continued tight closing of the valve under repeated operation and adverse conditions, and to produce a trap particularly well suited for high pressure systems.

With the above and other objects in view, the various features of the invention consist in certain novel features of construction, combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art from the following description.

In the accompanying drawing, Fig. 1 represents a section in elevation of a complete steam trap dissociated from the system; and Fig. 2 is a section of the thermostatic unit with attached valve. shown upon a somewhat enlarged scale.

Referring to the illustrated embodiment of the invention, the trap comprises a body II), which may be cast or forged, this body having an inlet branch l2 and an outlet branch or connection l4 in the usual manner. The outlet passage l6 may be provided with a removable and replaceable.

valve seat I 8, threadedly assembled with the body as indicated.

The upper portion of the body is conveniently provided with a cap 20, threadedly attached at 22 to the upper portion of the body. This cap carries the complete thermostatic unit and Valve assembly, as indicated clearly in the drawing.

Referring particularly to Fig. 2, the cap is provided with an internally threaded projection 24, within which is received and threaded a stem 26 having an integral head which is attached to and welded within a shallow recess 30 formed centrally in the head 32 of a bellows unit 34. The bellows unit is made, as is usual, with an integral head 32 having a recess formed therein, and is closed at its opposite end by an attached head 361 formed with an inwardly projecting or reentrant cup-like portion 38, which extends throughout the major portion of the length of the bellows unit in the normal position shown, serving two purposes. When the bellows unit is contracted under the influence of a vacuum, the extended portion 40 or bottom of the cup 38 contacts with the integral head of the bellows to provide a stop for limiting the movement of contraction, and in addition the reentrant cup portion occupies the major portion of the space within the bellows and substantially reduces the cubical capacity. This is advantageous, as it reduces the amount of thermostatic liquid which may be introduced into the bellows, and in consequence cuts down the effective quantity of thermostatic liquid subjected to change of temperature. The result is to produce a more sensitive and active unit whose response to changes of temperature is much faster than can be obtained with the conventional type of unit.

This unit may be conveniently filled interiorly through the employment of a capillary stem 42 mounted, in the end of the cup as indicated, and pinched or sealed ofi" at 44 after the vacuum fill is introduced. The bellows unit may be filled, as described in my previous Patent No. 1,816,142, with water under a vacuum, the amount of the fill depending upon the circumstances of use, as is common in the art. I

The valve unit is supported from the bottom of the cup 38, and is essentially shaped as a dumbbell with a ball at each end. As indicated, the valve comprises balls 46 attached to opposite ends of an intermediate bar or shank 48, which may be best accomplished in practice by forming the balls separately of uniform size and thereafter attaching the bar or shank by welding or equivalent means. This ball-ended valve is anchored at the upper end by assembly within the enlarged end 50 of a tubular sleeve 52, the enlarged end of the sleeve when in position holding the ball end in contact with a generally spherical depression. 54 formed in the bottom of the cup. This tubular sleeve is held in position by a socket ring 55, engaged by a spring clip 58, which may be sprung into a circumferential recess formed in the peripheral wall of the cup. In practice it will be obvious that the tubular sleeve and socket ring are assembled about the shank 48 before the balls are secured thereto, after which it becomes a simple matter to assemble the unit within the cup and lock it in place through the spring ring 58.

With this construction the ball-ended valve which engages with the edge of the valve seat 62 is enabled to seat itself in part through the shape of the valve, and in part through the swivel connection at the anchoring end, it being noted that the shape of the holding cage permits general swiveling movement of the ball, and the diameter of the sleeve 52 being somewhat larger than that of the shank permits limited movement therewithin. The anchoring of the ball-ended valve at the bottom of the reentrant cup and adjacent the fixed end of the bellows also serves to produce a better and more uniform seating thrust upon the valve than is normally possible where the valve is attached to the thermostatic unit in approximately the plane of the movable end of the bellows.

What is claimed is:

1. A steam trap comprising a body having a valve seat, a bellows unit within said body and having one end secured thereto, a head havthe free end of said bellows unit, said head having a cup-shaped reentrant portion extending into the interior of said bellows unit, a valve having a shank portion provided with a ball portion at one end and a curved seating surface at the opposite end thereof, a sleeve surrounding said shank portion, said sleeve being enlarged at one end, and means for securing said sleeve within said reentrant portion in such manner that the enlarged end of said sleeve cooperates with the inner wall of said reentrant portion to form a swivel mounting socket for said ball portion, the opposite end portion being disposed in cooperative relationship with said valve seat.

2. A steam trap comprising a body having a valve seat, a bellows unit within said body and having one end secured thereto, a head sealing the free end of said bellows unit, said head having a cup-shaped reentrant portion extending into the interior of said bellows unit, a valve having a shank portion provided with ball portions at opposite ends thereof, a sleeve surrounding said shank portion, said sleeve being enlarged at one end, and means for securing said sleeve within said reentrant portion in such manner that the enlarged end of said sleeve cooperates with the inner wall of said reentrant portion to form a swivel mounting socket for one of said ball portions, the opposite ball portion being disposed in cooperative relationship with said valve seat.

3. A steam trap comprising a body having a valve seat, a bellows unit within said body and having one end secured thereto, a head sealing the free end of said bellows unit, said head having a cup-shaped reentrant portion extending into the interior of said bellows unit, a valve having a shank portion provided with ball portions at opposite ends thereof, a sleeve surrounding said shank portion, said sleeve being enlarged at one end, and means within said reentrant portion for securing said sleeve therein in such manner that the enlarged end of said sleeve cooperates with the inner wall of said reentrant portion to form a swivel mounting socket for one of said ball portions, the opposite ball portion being disposed in cooperative relationship with said valve seat.

WALTER B. CLIFFORD.

CERTIFICATE OF CORRECTION. Patent No. 2,27 6,951. March 17, 1.91m.

WALTER B. CLIFFORD.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows; Page 2, first column, line 9, claim 1, for "a head hav-" read -a head sealing--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of May, A. D. 19kg.

Henry Van Arsdale, (seal) Acting Commissioner of Patents. 

